In fields such as the development of pharmaceuticals, agrochemicals and in medicinal discovery chemistry, there is an unmet need for conjugate additions with electron deficient boronic acids and esters. Some recent advances in the development of transition-metal-catalyzed carbon-carbon bond-forming chemistries are reviewed in Rouhi, “Fine Chemicals”, Chemical & Engineering News, Sep. 6, 2004, pages 49-67.
Additionally, few π-bonded hydroquinones are known. See Moussa, et al., “η5-Semiquinone Complexes and the η4-Benzoquinone of (Pentamethylcyclopentadienyl)rhodium and -irridium: Synthesis, Structures, Hydrogen Bonding, and Electrochemical Behavior”, Organometallics 23: 6231-38 (2004) and Amouri, Eur. J. Inorg. Chem., page 3808 (2005). For example, complexes containing 1,4-hydroquinone (H2Q) π-bonded to a transition metal are of substantial interest because of the importance of quinonoid molecules in mediating proton and electron transfer reactions. See: Pierpont, C. G.; Langi, C. W. Prog. Inorg. Chem. 1994, 41, 331. Ebadi, M.; Lever, A. B. P. Inorg. Chem. 1999, 38, 467. Coenzyme Q: Biochemistry, Bioenergetics and Clinical Applications of Ubiquinone; Lenaz, G., Ed.; Wiley: New York, 1985.
Those skilled in the art desire new uses of hydroquinone complexes. Embodiments of the subject invention satisfy this need and others.